1. Field of the Invention
The present invention relates to a hot water injection apparatus for a water cooling engine aiming to shorten a time of the warming-up operation, in which the density of the air-fuel mixture is high, so as to save the fuel consumption.
2. Description of the Prior Art
Conventional water cooling engine have a disadvantage that it takes a long time for the cooling water in the cylinder block to rise from a cooled condition to a heated condition during the warming-up operation. During the warming-up operation the density of the air-fuel mixture is maintained in a high condition by a mechanism, for example, an automatic choking mechanism until the temperature of the cooling water in the cylinder block rises to more than about 50 degrees.
Moreover, the uncombusted air-fuel mixture is exhausted during the warming-up operation especially in cold season, because the engine is governed at a high rotative speed by advancing the ignition timing in order to shorten a time of the warming-up operation. The uncombusted air-fuel mixture causes a pollution problem due to the hydrocarbon and does not enable an energy saving.
At a parking lot around a department store and a railroad station etc. a driver who leaves the car feels the irritation of his eyes or the stimulation of his nose or throat by a large quantity of the hydrocarbon exhausted from many cars under the warming-up operation. These conditions are typical for causing air pollution due to the hydrocarbon. It is experienced in cold season for a car that has come to a stop when it is driven without the warming-up operation, or that the engine was stalled due to a wet spark plug when the engine has been chocked too much.
Once the water cooled engine is stopped, the temperature of the cooling water heated by the engine during the operation falls to normal temperature taking about 30 minutes to 1 hour. Therefore the warming-up operation is repeated every time starting the engine. The car is now frequently used for the purpose of means for moving for a short time of 5 to 10 minutes, for example, for commuting, shopping and moving on business or leisure. In these circumstances, a car has a tendency to repeat such a warming-up operation several times a day in cold season.
Various apparatus have been proposed so far to store the high temperature cooling water heated by the engine during the normal operation and to make use of it for the next warm-up so as to shorten a time of the warming-up operation.
For example, laid open Japanese utility-model application No. U63-75525 discloses a water cooling system which is provided with a thermal insulation tank. The tank is situated in a bypass circulation line which returns the cooling water from a cooling water outlet of the engine to a cooling water inlet without passing through a radiator. A valve actuated in response to on and off of an ignition switch is fixed to an inlet and an outlet of the tank. Japanese patent application of laid-open No. P63-5107 discloses the same water cooling system with a thermos bottle as the aforementioned system except that the valve is actuated by an electromagnetic thermostat. The disadvantage of the systems is that the fixation of the valves makes the valves control complex and make the systems expensive and that the same level of the inlet and the outlet of the tank prevents the cooling water stored in the tank from flowing out smoothly.
Japanese laid open utility-model application No. U63-73578 also discloses a water cooling system which is provided with a sealed thermal insulation tank. The tank is communicated to the water cooling line through a valve and is connected to a means for increasing and decreasing the internal pressure of the tank. When the engine is stopped, the cooling water is sucked in the tank and insulated. Then the engine is started, the cooling water is returned to the water cooling line. The disadvantage of the system is that the installation of the valve and the pressure increasing and decreasing means makes the system control complex and difficult.
Thus, having many disadvantages, the previous systems have not been put into practical use yet.